""" Catalog module. """ from .providers import Provider class Catalog(object): """ Object provides catalog. """ def __init__(self, *used_providers): """ Initializer. """ self._clean_unused_providers(used_providers) def _clean_unused_providers(self, used_providers): """ Sets every catalog's provider in None except of `used_providers` list. :param list|tuple|set used_providers: :return: """ used_providers = set(used_providers) for attribute_name in set(dir(self.__class__)) - set(dir(Catalog)): provider = getattr(self, attribute_name) if not isinstance(provider, Provider): continue if provider not in used_providers: setattr(self, attribute_name, None)